The Circulatory System

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Across
  1. 4. the only white blood cells that contain histamine
  2. 6. the process that produces blood cells
  3. 9. the outermost protective layer of the heart
  4. 12. the organ where blood goes to be oxygenated
  5. 14. one of two upper chambers in the heart that receive blood from veins
  6. 16. a fibrous sac that encloses the heart and keeps it in a stable location
  7. 18. records the electrical signal from the heart
  8. 20. one of two lower chambers in the heart that forcefully pump blood out
  9. 21. a protein inside red blood cells that carries oxygen
Down
  1. 1. largest artery of the body
  2. 2. when the heart muscle contracts
  3. 3. when the heart muscle relaxes and the chambers fill with blood
  4. 5. largest vein of the body; divided into superior and inferior parts
  5. 7. the heart is located behind and slightly to the left of this bone
  6. 8. the location where stem cells are produced and give rise to different blood cells
  7. 10. the process by which a blood clot is formed
  8. 11. white blood cells that include B cells and T cells
  9. 13. clear liquid part of blood that remains after blood cells and clotting proteins have been removed
  10. 15. a protein involved in forming blood clots
  11. 17. a thin serous membrane lining the cavities of the heart
  12. 19. name of the student who created this puzzle